Guard for mechanical power press

ABSTRACT

An adjustable barrier guard on a mechanical power press consisting of a three-panel cage for enclosing the sides and front of the point of operation of the machine. The side panels are hinged to the press and pivotally support the front panel with all swingable to fully open positions for set up purposes, being mechanically locked and electrically interlocked in the operating position. Each panel is a rectangular frame supporting upper and lower rows of vertically disposed facing loops being individually vertically adjustable and clamped to form a closed protective barrier or any aperture configuration between the rows.

United States Patent [191 Connors et al.

[ GUARD FOR MECHANICAL POWER PRESS [75] Inventors: John J. Connors, Fredericktown; Charles C. Smith, Lucas, both of Ohio [73] Assignee: The Tappan Company, Mansfield,

Ohio

[22] Filed: Apr. 27, 1972 [21] Appl. No.: 248,068

[52] US. Cl 74/612, 83/546, 100/53 [51] Int. Cl. F16p 3/00 [58] Field of Search 74/612, 613, 608; 83/544, 83/545, 546; 100/53 [56] References Cited UNITED STATES PATENTS 2,503,144 4/1950 Willers 74/612 2,868,569 l/l959 Madden.... 83/546 X 3,587,344 6/1971 Plumb 74/ 6l2 [111 3,798,998 [451 Mar. 26, 1974 11/1931 Freeburg 74/612 Primary Examiner-Charles J. Myhre Assistant Examiner-F. D. Shoemaker Attorney, Agent, orFirm-Donnelly, Maky, Renner & Otto [5 7] ABSTRACT An adjustable barrier guard on a mechanical power press consisting of a three-panel cage for enclosing the sides and front of the point of operation of the machine. The side panels are hinged to the pressand pivotally support the front panel with all swingable to fully open positions for set up purposes, being mechanically locked and electrically interlocked in the operating position. Each panel is a rectangular frame supporting upper and lower rows of vertically disposed facing loops being individually vertically adjustable and clamped to form a closed protective barrier or any aperture configuration between the rows.

9 Claims, 4 Drawing Figures GUARD FOR MECHANICAL PowER PRESS I BACKGROUND OF THE INVENTION This invention relates to guards for mechanical power presses wherein material is positioned and work performed by shearing, punching, forming or assembling, and more particularly to a barrier type of guard to enclose the point of operation of such a machine and thereby protect against intrusion of a part of the body of the operator between the moving parts of the press.

The use of point of operation and barrier type guards for power presses has become widespread in the industry and in fact is essential and required to assure operational safety for this class of machines. It is of course possible to completely isolate the operating area with non-penetrable barriers and in conjunction with mechanical and electrical interlocks assure that safe operating conditions exist. However, it is also essential to the production capabilities of the machine that the point of operation be viewable by the operator, so that control can be exercised over the manufacturing process to assure proper operation and to avoid damage to the machine. The cage type of enclosure has been found readily suitable for these purposes and it is known to provide some degree of adjustment in setting the configuration of the cage so as to facilitate the placing and removal of parts from the press and some degree of access for clearing supervision. Most of these devices, however, are quite limited in versatility and thus are not safely amenable to a wide range of manufacturing processes or part configurations that may be desired to perform.

SUMMARY OF THE I VENTION Therefore it is one object of this invention to provide an improved barrier guard for such power presses and the like having improved versatility than prior known devices within rigid point of operation safety standards.

It is another object of this invention to provide an improved barrier guard for power presses and the like which provides access openings variable in elevation relative to the point of operation and of minimum needed degreesof access.

It is a further object of this invention to provide an improved barrier guard for power presses and the like in which various configurations of access apertures can readily be formed in setting up the press for particular operationsf It is a still further object of this invention to provide such an improved barrier guard for power presses which is readily disengaged from the machine during down time for complete access to the operating area.

It is a yet further object of this invention to provide an improved barrier guard for such power presses which is especially suited for high production manufacturing and provides greater safety than prior known devices which it replaces.

These and other objects of the invention are realized in the embodiment of the invention to be described in detail in apparatus which forms a three-panel cage type of barrier guard, each panel consisting of two rows of opposed and adjustably mounted facing loop elements which are individually relatively movable toward one another to form various desired locations and configurations for access apertures to the point of operation. The side panels are pivotally mounted to the frame of the press and in turn pivotally support the front panel, being secured'in the operating position by clamps and hinge pins which are releasable to allow swinging movement of the panels for full access to the operating area of the machine.

Other objects and advantages of the present invention will become apparent as the following description proceeds.

To the accomplishment of the foregoing and related ends, the invention, then, comprises the features hereinafter fully described, the following, description and the annexed drawings setting forth in detail a certain illustrative embodiment of the invention, this being indicative, however, of but one of the. various ways in which the principles of the invention may be employed.

BRIEF DESCRIPTION OF THE DRAWINGS In said annexed drawings: 9 FIG. 1 is a partial isometric view of a mechanical power press having the adjustable barrier guard of the instant invention in closed position about the point of DESCRIPTION OF THE PREFERRED EMBODIMENT OFTHE INVENTION Referring now to the drawings and more particularly I to FIG. 1 there is shown an embodiment of the barrier guard 10 in placement in operating position on an open back inclinable (OBI) power press 11 open at the front and both sides.

It will be clear from the following that such barrier or gate guards can be adapted to different types of presses, as well as other types of machineswhich may require comparable protection for safe operation.

The OBI-press 11 comprises a typical base structure 12 inclinably supporting the press body 14, the latter adjustable by means of an inclining mechanism, not shown, located at the rear of the press and capable of varying the degree of both forward and backward inclination. The drive mechanism generally indicated at 15 includes a flywheel 16 located at the top portion of the press 11 and is inclinable therewith as is the typical bed and bolster 18, the latter including slots 19 therein for attachment of a lower die 20 adapted to receive formed parts for example. An upper die 21 is supported for reciprocation relative to the lower die 20 by means of a conventional mechanism therebove receiving impetus from the flywheel 16. The body 14 of the press 11 is of.

els being electrically sensed to prevent operation of the press in other than the completely closed condition as will be described. All of the panels 28-30 of the guard are substantially the same, varying in dimensions however if needed to span the related portions of the operating point 25, the mounting arrangement therefor, and including slight constructional difference to accommodate folding together of the panels to form a. secure enclosure in the fully closed condition.

It is apparent, however, that suitable apertures may be provided in the barrier guard to allow for operation of the press 1 1 in a production manner without the necessity for opening any of the panels 28-30 to expose the operating point 25, such apertures including for example an exit aperture 31 in the left side panel 29 where sheets of scrap material 32 for example are discharged in a punching operation. Similarly, an entry material aperture would be included on the opposite side panel 28 for feed of the stock to be processed in a right to left feeding operation. Other apertures may be included as, for example, an aperture 34 in the front pan'el 30 for operator access to the work performing area 26. Well established standards have been formulated for size, shape and location of apertures in barrier guards and the like to preclude the possibility of pinch points and any other inadvertent entry of hands or fingers to the point of operation with the barrier in place. The requirements of these standards are often stringent and have been devised having in mind the conventional forms of barrier guards.

The barrier guard 10 of the instant invention is especially advantageous in this regard in meeting these standards, not only in providing a secure guard, but also in providing a structure which can be readily varied by the operator during the set-up procedure to accommodate a wide range not only of size of parts but also of shape or configuration of same and path of movement into and out of the operating point 25 with respect to the work performing area 26 of the machine. Thus, for example in FIG. 1 it is seen that an exit aperture 31 has been provided which closely conforms to the configuration of the run-out material 32, leaving only minimal spacing thereabout so as to preclude operator access physically to the area 26 without fully opening at least the front panel 30 forming the barrier, which bythe interlock system referred to assures stopping of the press.

Referring now to the various detailed views of the barrier guard 10, the front panel 30 of same comprises a generally rectangular frame 35 consisting'of a pair of vertically disposed side bars 36, 37 and upper andlower bars 38, 39 welded or otherwise rigidly fastened together and dimensioned to conform approximately to the dimensions of the front projection of the operating area 25 of the press 1 1 defined by the overhang portion 24 and the bolster 18. The bars 36-39 are preferably formed of steel and are generally of square crosssection, with the upper and lower bars 38, 39 having respective extensions 40, 41 laterally beyond the side bars 36, 37 which'form a part of hinging and/or locking mechanism for such front panel. A pair of straps 42, 44 also preferably being bars of steel span the width of the front panel 30 and are secured thereto by means of bolts 45, 46 respectively, also including extensions 48, 49 thereon beyond the side bars 36, 37. All such bar extensions 40, 41, 48, 49 are vertically apertured to receive rods 50, 51 forming side hinge pins. The vertically spaced apart straps 42, 44 thus serve to add further rigidity to the front panel 30, but-primarily serve as a part of the guiding or clamping means for the two rows 52, 54 of adjustable elongated loop members 55 forming the screen or barrier face of the panel 30.

The elongate members 55 comprise loops of approximately one-fourth inch diameter cold rolled steel rods, each loop 55 having a curved end portion 56 and an elongated pair of parallel legs 58 dimensioned to be received in equidistantly drilled holes in the upper and lower bars 38, 39, extending beyond same and positioning the curved portions 56 adjacent one another between the straps 42, 44.

As seen most clearly in the sectional view of FIG. 4, the straps 42, 44 also include vertically extending arcuate notches 59 respectively in line with the drilled holes of the upper and lower bars 38, 39' and further receive a plurality of clamps 60 consisting of bar segments of generally rectangular configuration having mating arcuate notches therein to conform to the legs 58 of the loops 55. The bar segments 60 are retained in place by bolts 61 passing through the central portion thereof and threaded into the straps 42, 44 between the legs 58 of the respective loops 55. Thus for example, it will be clear that a bolt 61 may be loosened to allow vertical adjustment of the associated loop 55 in the upper row 52, being limited in upward adjustment by the abutment of the curved portions 56 of the loops 55 with the strap 42 and in lower adjustment by the length of the legs 58 of the loops 55.

As seen most clearly in FIG. 2, the upper strap 42 is locatedapproximately midway between the upper and lower bars 38, 39 of the frontpanel 30, with the lower strap 44 a relatively short distance above the lower bar 39. The lengths of the legs 58 of the loops 55 are so dimensioned to extend beyond the upper and lower bars 38, 39 respectively when the curved portions 56 of the loops are approximately central of the straps .42, 44 and to allow the curved portions 56 of the loops to be brought to positions closely adjacent the opposite straps. It is evident also from FIG. 2 that although the drilled holes in the bottom bar 39 are substantially in alignment with the drilled holes in the upper bar 38, the loops in the lower row 54 are offset between the loops in the upper row 52, with the lower clamp members 60 similarly positioned to allow each loop 55, except for end loops, to abut two opposed loops to provide a tightly closed configuration for the panel surface. It is apparent that the loops 55 could alternatively be positioned in alignment with one another with some degrading of the closing capability of the barrier guard 10 or that different configurations for the curved portions 56 in the loops could be utilized. It will be evident also that almost any configuration and size of aperture can be formed between the upper and lower rows 52, 54 of loops in the panels of the barrier guards, including a curved aperture and critical control over the width and heighth of the aperture and the elevation with respect to the point of operation'25.

v The side walls 28, 29 of the barrier guard are of almost identical configuration dimensioned to conform to the side access to the point of operation 25 and having upper and lower bars 64, 65 dimensioned by the length of the side bars 66, 67 to fit between the upper and lower bars 38, 39 of the front panel 30 when adjacent thereto. The straps 68, 69 on the side panels 28, 29 wre similarly offset with respect to the front panel straps 42, 44, extensions thereon again forming a part of the hinge assembly between the side and front panels. In other respects, however, the side panels 38, 29 are similar to the front panel 30 and include upper and lower rows of loops 70, 71 which are individually adjustable to form apertures between the straps 68, 69 or between the rows of loops 70, 71 themselves and portions of the press.

Support of the complete barrier guard is provided by plates 72 bolted to the sides of the body of the press 11, and each having a section of vertically oriented pipe 74 welded thereto. A somewhat longer section of pipe 75 is horizontally disposed and welded to the top bar 64 of eachof the side panels 28, 29 and a steel hinge pin 76 of right angle configuration is received in the respective pipe sections 75. A flange 78 is welded to the hinge pin 76 to seat on each vertical pipe section 74 for support of the side panels allowing pivotal movement of same. A pair of bolts 79 are threaded into the vertical pipe sections 74 and may be drawn into abutment with the hinge pins 76, preventing rotation of the hinge pin in the pipe sections 74 and forming the locking mechanism for the side panels. Similar bolts 80 in the horizontal pipe sections 75.serve to retain the side panels against lateral movement but allow removal of same, if desired, by sliding off the hinge pins 76.

As previously indicated, the extensions of the upper and lower bars 38, 39, 64, 65 of the side and front panels are apertured to receive the hinge rods 50, 51 to support and retain the front panel 30 in position. It will be apparent in this construction that the front panel 30 may be swung either right or left upon removal of one of the hinge pins 50, 51. Preferably one hinge rod 51 is secured in place by means of a cotter pin 81, with the other rod 50 removable to gain access to the operating area 25. In this arrangement of the invention an electrical contact making device 82 is mounted on the inside of the panel 29 adapted for abutment by the front panel 30 when the latter is in the completely closed condition to establish an electrical circuit and assure that the press clutch is operable only in such condition, such interlock devices being well understood in the art. The device 82 includes a bolt 84 mounted on the front panel 30 and engageable with a plunger 85 loaded by a spring 86, to move the plunger 85 and make an electrical circuit via wires 88. Similarly, a pair of microswitches 89 are located on the body of the press 11 adapted for abutment and actuation by the side bars 66 of the side panels 28, 29 to establish an electrical circuit only when the side panels 28, 29 are in the fully closed position.

Referring again to FIG. 1, it is clear then that apertures may be provided not only between the strap members 42, 44 of the front panel 30 and between the straps 68, 69 of the side panels 28, 29, but also that apertures can be provided between the legs 58 of any of the loops and portions of the press structure itself. Thus as seen in FIG. 1 a central group of loops 90 in both rows of loops 70, 71 in side panel 29 is elevated to establish the aperture 31 to the point of operation 25, in this instance between the ends of the legs of the loops in the lower row of loops 71 and the edge of the bolster 18 of the press.

Similar openings can be formed in other area of the barrier guard 10 and different dimensions for panels 28-30 can be utilized for specialized forms of presses. However, it is apparent that great versatility is afforded by the apparatus of the instant invention and that a single configuration'of barrier guard 10 is adaptable to many types of jobs or press configurations and that superior safety features can be realized. An example on this last order would be a straight side press in which only the front is open for insertion and removal of the material being processed.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. An adjustable barrier guard for mechanical power presses and the like, comprising a frame, barrier means supported on said frame to form a protective enclosure for a side of the press and providing at least one limited access opening therein, said barrier means including multiple vertical members individually adjustable relative to the frame in upper and lower series movable by such adjustment toward and away from each other to locate and determine the size and configuration of the access opening or-openings within said frame.

2. A guard as set forth in claim 1, wherein said frame is provided with means for pivotally mounting the same on said press for swinging movement relative to the operating area thereof, and further including means for locking said frame in closed condition.

3. A guard as set forth in claim 2, wherein said frame forms one side of a cage enclosing the machining area of the press, second and third similarly formed frames are provided with means forpivotal mounting to the press frame to swing between open and closed positions relative thereto.

4. A guard as set forth in claim 3, wherein said first frame is pivoted and lockable in closed condition to one of the second and third frames, with the former at the front and the latter at the respective sides of the press operating area.

5. A guardas set forth in claim 1, wherein said vertical members comprise loops of rigid material slidably mounted and lockable in said frame, the loops of said first series being offset with respect to and facing the loops of said second series of said frame.

6. A guard as set forth in claim 4, wherein each said frame comprises a generally rectangular structure having upper and lower straps spanning the same, with said vertical members thereof being guided in said straps, and clamping means for respectively engaging the upper and lower series thereof for locking the same releasably in vertically adjusted positioning at intermediate elevations within the frame.

7. A guard as set forth in claim 1, wherein said frame comprises a generally rectangular structure having upper and lower straps spanning said structure, with said vertical members being guided in said straps, and clamping means for respectively engaging the upper and lower series for locking the same releasably in vertically adjusted positioning at intermediate elevations within the frame.

8. A guard as set forth in claim 7, whereinsaid vertical members comprise loops of rigid material slidably mounted and lockable in said frame, the loops of said first series being offset with respect to and facing the loops of said second series.

9. A guard as set forth in claim 8, wherein said framecomprises a generally rectangular structure having upper and lower straps spanning said structure, with said vertical members being guided in said straps, and clamping means for respectively engaging the upper and lower series for locking the same releasably in vertically adjusted positioning at intermediate elevations within the frame. 

1. An adjustable barrier guard for mechanical power presses and the like, comprising a frame, barrier means supported on said frame to form a protective enclosure for a side of the press and providing at least one limited access opening therein, said barrier means including multiple vertical members individually adjustable relative to the frame in upper and lower series movable by such adjustment toward and away from each other to locate and determine the size and configuration of the access opening or openings within said frame.
 2. A guard as set forth in claim 1, wherein said frame is provided with means for pivotally mounting the same on said press for swinging movement relative to the operating area thereof, and further including means for locking said frame in closed condition.
 3. A guard as set forth in claim 2, wherein said frame forms one side of a cage enclosing the machining area of the press, second and third similarly formed frames are provided with means for pivotal mounting to the press frame to swing between open and closed positions relative thereto.
 4. A guard as set forth in claim 3, wherein said first frame is pivoted and lockable in closed condition to one of the second and third frames, with the former at the front and the lattEr at the respective sides of the press operating area.
 5. A guard as set forth in claim 1, wherein said vertical members comprise loops of rigid material slidably mounted and lockable in said frame, the loops of said first series being offset with respect to and facing the loops of said second series of said frame.
 6. A guard as set forth in claim 4, wherein each said frame comprises a generally rectangular structure having upper and lower straps spanning the same, with said vertical members thereof being guided in said straps, and clamping means for respectively engaging the upper and lower series thereof for locking the same releasably in vertically adjusted positioning at intermediate elevations within the frame.
 7. A guard as set forth in claim 1, wherein said frame comprises a generally rectangular structure having upper and lower straps spanning said structure, with said vertical members being guided in said straps, and clamping means for respectively engaging the upper and lower series for locking the same releasably in vertically adjusted positioning at intermediate elevations within the frame.
 8. A guard as set forth in claim 7, wherein said vertical members comprise loops of rigid material slidably mounted and lockable in said frame, the loops of said first series being offset with respect to and facing the loops of said second series.
 9. A guard as set forth in claim 8, wherein said frame comprises a generally rectangular structure having upper and lower straps spanning said structure, with said vertical members being guided in said straps, and clamping means for respectively engaging the upper and lower series for locking the same releasably in vertically adjusted positioning at intermediate elevations within the frame. 